It's the year 2035 and Eden Sinclair (RHONA MITRA) is a major in the British military, an efficient soldier who carries out various jobs for Bill Nelson (BOB HOSKINS), the chief of the Department of Domestic Security. He reports directly to Prime Minister John Hatcher (ALEXANDER SIDDIG) and his right-hand man, Michael Canaris (DAVID O'HARA), both of whom are worried about a recent development.
It seems that nearly 30 years ago, an outbreak of the deadly and contagious Reaper virus spread like wildfire throughout Scotland. As a last resort, the Brits literally walled in the population with a thirty-foot-high barrier, ordered that no one be let in or out, and hoped that would prevent the problem from spreading.
Now, however, there's been an outbreak in London, and the government is desperate for a solution. They hope they've found it in surveillance footage of Glasgow that's recently shown activity in the streets where everyone presumably would have been long dead. Their hopes are buoyed by the earlier work of a scientist by the name of Kane (MALCOLM McDOWELL) who was working on a cure, but he hasn't been heard from in a very long time.
Nevertheless, he or someone following in his footsteps is their only viable hope, so Nelson opts to send Eden on a recon mission to find out what's going on and bring back a cure. Joining her is military man Norton (ADRIAN LESTER); armored transport drivers Chandler (RICK WARDEN) and Read (NORA-JANE NOONE); gunners Carpenter (LESLIE SIMPSON) and Miller (CHRIS ROBSON), and researchers Dr. Talbot (SEAN PERTWEE) and Dr. Stirling (DARREN MORFITT).
So as not to draw any attention, the mission is top-secret, and Eden and her team are given 46 hours to get in, find the cure, and get out. Once in country and searching for Kane, they encounter a bunch of punk survivors led by the brutal but charismatic Sol (CRAIG CONWAY) and his heavily tattooed woman, Viper (LEE-ANNE LIEBENBERG), none of which are happy to see them, especially once the bullets start flying.
From that point on, and after rescuing one of Sol's prisoners, Cally (MYANNA BURING), and then having to contend with Kane's forces, Eden and her team do what they can to survive, all while looking for that much-needed cure.